Am I understanding the concern about the lower control arm correctly? Now that there is no torsion bar, the lower control arm is simply sticking out to the spindle with no triangulation type support?
If I am understanding correctly, then IMO, you'll need some sort of diagonal link similar to the setup in the Bobs Pro Fab kit. Problem with this I know is...raises cost of product, and will require more fabrication done by the customer to weld tabs in place to accept the diagonal link. Unfortunately, I dont think you'll get around not having something forming some triangulation for stability.